EP0225632A2 - Method and apparatus for integrated sampling and in-line sample splitting of disperse products from transport pipes or to product stream transfer stations - Google Patents

Abstract

The method involves taking a subsample from a main product stream and, by sample separation, obtaining from this subsample an analysis sample to be analysed and a residual amount. To provide a method and apparatus for representative sampling, in terms of time and place, and sample separation to obtain a small analysis sample stream suitable for subsequent on-line sample analysis, the invention provides that sampling and sample separation are carried out continuously in-line in direct succession and, with sampling, a representative subsample stream of up to 1/100 of the main product stream is taken by a rotatably driven collecting head (12) which is arranged at the inlet of a collecting line (30) and the collecting opening (10) of which is at least one circular sector, which can be rotated by its tip about the centre axis of the product stream transport pipe. Immediately after sampling, the subsample stream is continuously separated by a sample separator (60) by up to three powers of ten. The individual samples produced during sample separation are drawn off individually or randomly, combined by a concentrator (71), in such a way that the subsequent analysis can be carried out directly on-line without any appreciably delaying intermediate storage. Various designs of the sampler (9) and the sample separator (60) are explained. <IMAGE>

Description

The analysis of product qualities in production processes takes place in particular in the production of bulk goods on the basis of selected partial samples which are taken from the process. For the subsequent analyzes in the laboratory, usually only small sample quantities of a few grams or even milligrams are required, so that the task of extracting the smallest, representative sample quantities from large production streams of a few tons per hour can only be reproducibly and reliably achieved if initially larger ones Partial quantities are removed and the small, required analytical sample quantities are then obtained by controlled representative sample division.

The so-called off-line quality control for disperse products provides an analysis result for product evaluation within a few hours to a day. However, sampling and sample division generally takes place. only at intervals and still rather simple. With regard to the procedure, the reproducibility and the systematics, it has to be regarded as by far the weakest point in the process information chain, even in comparison to the off-line measuring devices that are now available, even if the first continuously working samplers have already been announced, but with whom do not immediately obtain any analytical sample quantities. These samplers would therefore work at most quasi-continuously, since the requirements of the analysis device downstream of them are transferred to them.

Increasing automation, rationalization and constant quality control of product streams make manual sampling at intervals appear extremely questionable, especially because of their limited representativity, if the laboratory analyzes are carried out with highly precise measuring devices. The characterization of disperse product properties by at least quasi-continuous particle size analysis, e.g. With a laser diffraction spectrometer, this discrepancy is now particularly noticeable.

The development step for on-line production control with the aim of process control ultimately requires a removal interface with which it is possible to quickly process e.g. a few minutes to have a small amount of analysis sample that is not only representative but also quantitative for analysis.

A systematic classification of the conceivable types of withdrawal for disperse products must distinguish between production processes in which the product is transported in a fluid carrier stream, which can be wet (water) or dry - (air), or as separated, carrier-free bulk material, e.g. behind the cyclone, mill, sifter, bunker or the like and is delivered from a transport line or a chute or from a conveyor belt or handed over for further processing.

The known sampling devices, e.g. Pipette, piercer or sample lifter, immersion collector, sampling valve, stationary suction probe, sample probe, sample scraper, pendulum or impact sampler, half-open slotted sampling tube or screw conveyor, each of which only records a small part of the cross-sections of the production flow to be recorded, are for the complex tasks in on -line operation not suitable or only suitable to a limited extent.

In the case of the tape handover, sampling devices are known which are available at product handover points, e.g. the transfer from one conveyor belt to another conveyor belt, as so-called slot samplers are intermittently moved back and forth under the product transfer point and represent a problem solution for this level, linear removal problem that can be used for less demanding applications if the division ratio does not exceed 1: 100.

In the case of rotationally symmetrical process cross sections, which are customary for the transport of disperse products in a wet or dry means of transport (transport lines), known intermittent or rotating slot samplers cannot be used, however, if the accuracy of the statement is high.

The invention has for its object to provide a method and an apparatus for sampling from streams of dispersed products from transport lines or at product transfer points and sample division on a representative small sample stream suitable for a subsequent on-line sample analysis.

Methods and apparatus that solve this problem are characterized with their configurations in the claims.

In order to meet the requirements in on-line operation, a continuous and representative sampling of up to 1/100 of the main product flow takes place in a rotationally symmetrical transport cross-section of the Production process. The use of a circular sector-shaped removal opening that radially sweeps over the entire transport cross-section ensures that all areas of the transport cross-section are taken into account representatively during sampling and that a sufficiently large partial sample (up to 1/100 of the main product stream) is taken integrally so that it is connected downstream in the line Sample dividers can also be temporally representative divided down to the small sample mass flow required for a representative sample analysis in a ratio of up to 1: 1000. In this way, only the smallest sample stream required for the downstream sample analysis, which can be a grain size analysis, is led out of the process, while the remaining partial stream is immediately in. the process product stream or main product stream remains or is returned in this.

The new method and the corresponding device solve the problem in such a way that, on average, at least one partial stream is continuously taken from the entire transport cross-section of the product and fed to the in-line sample division. This is achieved in that the opening cross-section for the removal of the partial flow can be adapted to the local and temporal removal situation both in terms of the shape and in terms of its position in time.

Conventional partial flow sampling methods, e.g. suction with probes according to VDI guideline 2066, traverse the product flow cross-section point-by-point according to a predetermined grid at a time interval controlled by the sample analyzer. This sampling method has neither a high, local resolving power nor a meaningful integration effect with regard to the entire transport cross-section, since the weighting of the individual sampling points from hypothetical assumptions about the quality of the quasi-steady flow and the homogeneity of the distribution of the dispersed product in the transport cross-section and about the Time must run out.

The shape and time are adjusted for the removal of the partial flow from the main flow via a removal cross-section or a removal opening, the outer boundaries of which form a circular sector with the opening angle a, which slowly rotates with its sector tip around the pivot point located in the tube axis of the main product transport stream. The speed of rotation w is chosen only so high that there are no disruptive effects on the product flow. This means that sampling is representative of the cross-section.

The extraction ratio of partial flow to main flow achieved is αI360 °. The radius of the circular sector must be at least equal to or greater than the radius of the cylindrical transport line for the main stream, so that all the area components are completely covered within one revolution. One full revolution corresponds to an integration across the entire main stream transport cross section. The speed of rotation must not coincide with any fluctuation frequencies of the main stream. With the number of integration cycles, from which the entire partial sample is formed summarily, its reliability for assessing the product flow increases.

Instead of a single circular sector, two opposite circular sectors can also be designed as a removal opening. The extraction ratio is 2 «/ 360 ° if the angles are the same or (a, + (2) / 360 ° if different sector angles are used.

In the case of coarse particles in the main product flow, the integration effect may be discontinuous. This is avoided by attaching a cone-shaped tip or a deflection cone, which is so large in the circular base that the smallest sector-shaped removal opening close to the fulcrum is considerably larger in the tangential direction, preferably at least ten times larger than the dimensions corresponds to the coarsest particles contained in the main product stream.

The deflection cone is to be made as steep as the deflection cone over which it is arranged so that the particles hitting the immediate center are easily removed and, on average, are representatively directed into the removal opening. This also prevents jamming of coarse particles in the inlet opening. A sieve with large meshes can also be provided between the main line and the intermediate piece to make it even.

With on-line measuring cycles of approx. 5 minutes in duration with a measuring time of one minute and constant sampling, on average partial quantities from 100 to 200 integration revolutions are obtained if the rotational speed is up to 1/2 revolutions per second. Since the formation of the removal opening with sector opening angles a below 5 ° is not technically recommended due to the increase in the border influences at small angles, the removal partial flow should be at least about 1.5% of the main product flow. The required continuous reduction to one Analysis sample stream is realized with the immediately downstream sample divider. As a guide, it can be considered that between 1% and 0.001% of the main product flow is required for the on-line analysis, whereby, as explained above, the sampling can perform the dividing step in the percentage range and the subsequent in-line sample division of the partial flow by appropriate The further reduction by an additional two to three powers of ten must be representative.

This can be realized in such a way that the continuous partial stream withdrawn with the circular sector removal opening is split into a discrete sequence of partial streams, which as individual streams by selected combination, e.g. every 8th, 16th or 32nd etc. individual stream are finally combined to form the analysis sample stream. Due to the strong subdivision into hundreds of individual streams and the systematic implementation of the sample collection, only very small systematic errors can be expected.

The invention allows a direct adaptation of the extraction of the analysis sample to the measuring ability of the on-line analysis system for the representative assessment of the product or process. The on-line analysis system used thus allows the process apparatus to be controlled and the analysis device to be connected to a continuously operating system in such a way that the validity and meaningfulness of the analysis results is not questionable about the function of the system. For this purpose, a process signal is obtained as a continuous time average. Ergodicity is not a prerequisite, as is the case with a shear mean value determination, i.e. the taking of individual samples does not mean that the sampling frequency is also stochastic as a random process. Ergodicity is difficult to check in the production process and is usually not given anyway in the case of fluctuating influencing variables and measured variables which make online process control or regulation necessary. A sample measuring device that is ready to measure every 10 minutes cannot achieve representative analysis results if an analysis sample is supplied to it every 10 minutes, the quantity of which only corresponds to the amount required by the analysis device and completely ignores what has happened between the sampling times in the production process.

The new device can basically have two different configurations. The first embodiment realizes the sampling method if the disperse products are contained in fluid transport means, that is to say conveyed in a carrier means. The second embodiment realizes the sampling of bulk goods in vertical transport lines or

Drop chutes in which the main product flow falls freely without means of transport. In the case of the first embodiment, in comparison to the second embodiment, the sequence of the sub-steps during sampling or generation of the partial flow, which is otherwise basically the same, additionally requires the simultaneous, isokinetic suction of the fluid or. Carrier medium flow can be guaranteed.

• Fig. 1 eine Schnittansicht einer ersten Ausführungsform für die Probenahme und -teilung eines trägermittelgeförderten Produkthauptstromes,
• Fig. 2 eine Schnittansicht einer zweiten Ausführungsform für die Probenahme und -teilung eines in einer vertikalen Transportleitung frei fallenden Produkthauptstromes,
• Fig. 3 eine Schnittansicht einer gegenüber Fig. 2 etwas abgewandelten Ausführungsform,
• Fig. 4 eine Schnittansicht von zwei Ausführungsformen des Probenteilers nach Fig. 2 zur Einstellung des Probenteilungsverhältnisses,
• Fig. 5 eine abgewandelte Ausführungsform mit einem als Riffelteiler ausgebildeten Probenteiler, und
• Fig. 6 eine gegenüber Fig. 5 abgewandelte Ausführungsform mit einer anderen Ausgestaltung der Sicherheitsabsiebung,
• Fig. 7 eine Schnittansicht einer weiteren Ausführungsform mit in-line hintereinandergeschalteten Riffelteilern als Probenteiler.

Exemplary embodiments of the new device are explained in more detail with reference to a drawing, in which:

• 1 is a sectional view of a first embodiment for the sampling and division of a carrier-conveyed product main stream,
• 2 shows a sectional view of a second embodiment for sampling and dividing a main product stream falling freely in a vertical transport line,
• 3 shows a sectional view of an embodiment somewhat modified compared to FIG. 2,
• 4 shows a sectional view of two embodiments of the sample divider according to FIG. 2 for setting the sample division ratio,
• 5 shows a modified embodiment with a sample divider designed as a corrugated divider, and
• 6 shows an embodiment modified from FIG. 5 with a different embodiment of the security screening,
• Fig. 7 is a sectional view of a further embodiment with in-line series corrugated dividers as sample dividers.

With reference to FIG. 1, which shows a device for integrating sampling and in-line sample division with isokinetic fluid or. Carrier means suction, a first embodiment of the method according to the invention is explained. A product main stream 1 flowing in a transport pipe meets a removal or in this case formed by a double sector. Mouth opening 10 of a rotatably mounted sampling head 12 of a sampler 9, which rotates slowly at the angular velocity ≈ about the transport pipe axis and through which a partial stream 2 is removed from the main stream 1. In the center of rotation, a sensor 11 is provided in or immediately in front of the removal opening 10, which contains the measurement information for setting a suction unit 70, e.g. a suction fan, for the isokinetic suction of the means of transport.

In the case of removal from a gas-solid two-phase flow, the sensor 11 can be a pressure bore with a subsequent capillary line, which measures the static pressure of the main flow and together with a second pressure bore tion in the suction pipe for measuring the static pressure in the partial flow provides the basic information on the isokinetic operation of sampling according to the known principle of differential pressure probes.

In the case of sampling from liquid-solid transport flows, the sensor 11 can be designed as a correlation element with which the correct removal speed for the partial flow to be extracted can be set by measuring the particle speeds in the main flow. Known embodiments of correlation measuring points see two optical sensors connected in series in the flow direction, e.g. Glass fiber sensors, from whose signal structure the speeds can be deduced by means of a correlation method via the transit time shift.

Behind the double sector of the removal opening 10, the cross section of the rotatably mounted, rotationally driven removal head 12 is deformed such that a transition cross section 13 from the rotating removal head 12 into a fixed circular-cylindrical removal line 30 is circular. From a manufacturing point of view, this is easily achieved with two triangular sheets, which are beaded in the respective axis of symmetry and folded at an angle (180-a), connected at the removal opening at the break point and covered with two conical half-shells, the half-shells connecting to a circular opening at the transition cross section 13 .

The fixed, elongated, curved sampling line 30 of the sampler 9 directs the partial stream 2 from the main stream 1 to an in-line sample divider 60 comprising a cylindrical head piece 31 rotating during operation and a downstream cylindrical stator 32. Both the head piece 31 and the stator 32 are divided with fixed internals in the form of axially parallel partition walls into sector-shaped guide channels 33, which are then individually transferred to a concentrator 71 in order to obtain the analysis sample stream from the divided sub-stream 2.

The removal head 12 and the rotating sample divider head piece 31 are driven by the same drive 14 (motor M), the gear ratios being chosen so that w2> ≈, without being an integral multiple, and w, again out of sync with a possible oscillation in the main stream 1 may be selected.

The sample divider 60 comprising a rotating head piece 31 and a fixed stator 32 can, together with the concentrator 71, also be installed directly in a main line 72 behind the removal head 12. The drive would then be implemented at the transfer cross section at different speeds by a common gear 15.

The concentrator 71 is designed in such a way that an analysis sample mass flow 3 required for the subsequent use can be preselected and set correctly by means of gradual combination. A remaining partial stream 4 is returned to the main stream 1 by the suction unit 70 or discarded.

The representative sample sample flow stream 3, which has been taken and divided, is used in a measuring section for on-line particle size analysis. After passing through a baffle disperser 80 supplied with compressed air, the sample stream is blown as free jet 81 through the measuring zone of a diffraction spectrometer 82. The widening free jet 81 is detected with a collecting funnel 83 and is returned to the main stream 1 either directly or via a separating cyclone 84. This separation in the cyclone 84, coupled with a flow filter 85, enables a conventional check of the measurement results achieved on-line.

2 shows the device for carrying out the method behind a transport line or a chute with the two cuts E-E and A-D.

In the top view A-D, a circular sector NMO can be seen in the left sector AMB as the rotating removal opening 10. The circular sector - encloses the angle between its corner points NO. The sector radius MN or MO is designed to be noticeably larger than the radius of the vertical main line or of the chute 72, which can be clearly seen in section E-E in section line A-B. The difference in diameter between the chute 72 and a sampler housing 16 is bridged with an intermediate piece 73. With the arrangement shown, all chute diameters that are smaller or equal to twice the sector radius MN can be equipped for sampling.

The removal opening 10 is located on the inlet side of a mouth funnel 18 which tapers in the flow direction and serves as a removal head, on a hollow deflection cone 17 which is mounted so as to be drivable in a rotationally drivable manner counter to the direction of flow. This results in the outlet opening 19 which is crossed out in the top view AD. The partial stream 2 which is removed by it flows into an around the axis of the deflecting cone 17 with the angular velocity ω ₂ circulating manifold 20. The main mass flow 1 falling past the discharge opening 10 or the outlet funnel 18 is returned to the center of the fall by a fixed first collecting cone 21 and passed on to a rotatable second collecting cone 22 with a subsequent central pipe outlet 23. The distributor pipe 20- is firmly connected to the second collecting cone 22. This is set in rotation by a motor 14 via a drive belt 28 at the angular velocity c.l2. As a result, the distributor pipe 20 also rotates at this angular velocity 02. The drive is arranged here outside the housing 16, so that both the motor 14 and its drive belt 28 have no product contact. The encapsulation of the drive space between the housing 16 and the internals 17, 18, 20, 21, 22 and 23 is achieved by the special design of a sealing brush 27, which at the same time acts as a cleaning element between the first or upper collecting cone 21 and the second or lower collecting cone 22 acts. The driven elements 17, 18, 20, 22 and 23 are mounted centrally on a bearing block 29. The deflection cone 17 and the mouth funnel 18 are driven via a transmission which also serves as a connecting element, the lower half 15 of which is built into the distributor pipe 20 and the upper half 24 of which is built into the deflection cone 17, due to the rotation of the lower collecting cone 22. An integrated drive is shown in Fig. 5 and described by this.

On the outside of the deflection cone 17, a cleaning brush 26 is fastened, which also rotates and keeps the first or upper stationary collecting cone 21 free of deposits on the inside and ensures a constant product outflow. The cleaning brush 26 is supported by the constant vibration of the device by means of a vibrator 51, as shown in FIG. 5. The rotating cleaning brush 26 lies opposite the mouth funnel 18 and is to be tared as a centrifugal mass so that the eccentric imbalance of the mouth funnel 18 is compensated for.

A corresponding centrifugal mass 25 to compensate for the eccentric imbalance of the distributor pipe 20 is to be provided on the second or lower, rotating collecting cone 22. It itself is kept free of deposits in the upper inlet area by the sealing brush 27, which is supported on the outer surface of the first or upper collecting cone 21. and is fixed or does not turn. In the case of a dust-protected design, the free passage cross section between the collecting cones 21 and 22 can be closed with a correspondingly rotationally symmetrical brush arrangement. This is particularly important if, as shown, the second collecting cone 22 from the outside, e.g. by means of the drive belt 28, is rotated and the housing bushings and the drive elements should not have any product contact.

A housing 34 of the downstream in-line sample divider is flanged to the sampler housing 16 below the cutting plane CD. The rotating distributor pipe 20 transfers the withdrawn partial flow 2 to a dividing funnel 35. In the top view A-D one can see in the sector CMD a partial opening 36 in the inner surface of the dividing funnel, which is sector-shaped and is delimited by the corner points RSTU. Through this partial opening 36 with the sector angle β between the legs MTS and MRU, β / 360 ° of the partial flow can fall through, while a remaining partial flow 4 (1-β / 360 °) from the dividing funnel 35 through its outlet opening 35 'into a lower return pipe 37 to main mass flow 6 not taken is returned. The bearing block 29 is fastened to the return pipe 37.

A slightly inclined safety sieve 38 is arranged below the partial opening 36, with which coarse spray particles 7, impurities or particles that lie outside the measuring range of the downstream sample analyzer can be separated from the analysis sample stream 3 and returned to the main pipe 6 in the return pipe 37. The analytical sample stream 3 thus prepared is directed into a sample delivery tube 39 and is led out of the combined sampler-sample divider for subsequent sample analysis or other use at the shaft transfer opening 40.

Fig. 3 shows in section E-E a central deflection cone 59, which is arranged above the deflection cone 17, that it is completely housed in the intermediate piece 73 from the height and above it, a large-meshed intermediate sieve 61 can be installed for uniform transverse distribution of the falling bulk material stream 1. In the quarter-circle partial section A-B, the base circles of the cones 59 and 17 arranged one above the other are shown as full circles in the plan view for clarity.

When transferring the analysis sample stream 3 which is led out of the process by means of the sampler and sample divider, it may be necessary to provide a suction device for dedusting at the transfer opening 40. Such an arrangement is shown in FIG. 3. An intake port 51 is arranged around the central transfer pipe 52 in such a way that an adjustable annular gap 53 is created around the transfer cross section 40. With a downstream suction unit 70 is the The smallest possible air flow required for dedusting is sucked in from the outside against and transversely to the direction of fall of the sample stream 3 through a filter 85.

For applications in which e.g. Due to changing main mass flows 1, an adaptation of the analysis sample flow 3 must be provided, the opening angle β is variable and e.g. adjustable according to a mass flow sensor 8. The actual mass flow value leads via a signal line 79 to the setting of the opening angle β.

Two embodiments of variable setting options for the removal opening angle β are shown in FIG. 4. In the lower half of the image, the top view representation of FIG. 2, sector AMB, is repeated in the top view in the lower left quadrant. Removal opening 10, outlet opening 19 and deflection cone 17 can be seen.

In the lower right quadrant, the setting of β, with folding chutes 41 is shown as the first embodiment. In the illustration, the three open chutes are crossed out at the passage openings. In section A-A, the triangular contour of the folding chutes 41 which are U-shaped in cross section can be seen in the top right in FIG. 4. The open position is shown in dashed lines. In the closed position, the open upper edge lies in the plane of the dividing funnel 35. When opening about an overhead pivot point 42, the folding chute 41 pivots through the angle φ from the closed position. The analysis sample stream 3 then passes through the safety sieve 38 into the sample delivery tube 39 to the transfer opening 40. When the folding chutes 41 are closed, the residual partial stream 4 returns to the main mass flow 6 into the return pipe 37.

A total of 15 folding chutes 41 are provided in a 90 ° segment, so that at β _1max = 90 ° up to 25% of the partial stream 2 removed can pass the sample division. If only one hinged chute 41 is open, β _1min = 6 °, ie only 1.67% of the partial stream 2 removed are passed on as analysis sample stream 3 for further processing.

The advantage of the chute arrangement is that it can be easily combined with digital control devices in which the opening or closing of individual folding chutes 41 can be switched discretely by simple yes / no decisions.

The two upper quadrants of the lower part of FIG. 4 show a solution for a stepless adjustment of the analysis sample flow. The sample divider opening angle β ₂ is set here by the rotation of a funnel segment 43. This is arranged in parallel above or below the dividing funnel 35 and can partially or completely cover the partial opening 36 of the dividing funnel 35 which is interrupted by 90 °. The discharged through the remaining portion of the opening 36 (ß ₂₎ partial flow falls, as can be seen, before entering the left in section AA back to the safety screen 38 as an analysis sample flow 3 in the sample delivery tube 39 to the transfer opening 40th

The mass flow ratio of analysis sample flow M _A to main flow M _H thus set is determined
M _A / M = (α · ß) / (360 °) ²
where a is to be structurally preselected so that the expected changes in mass flow AM _{H of} the main flow MH can be controlled with the variation 0 <β <90 °.

5 shows a modified embodiment of a combined in-line sampler with a downstream sample divider.

Both the sampler 9 and the sample divider 60 are modified. The sample divider here is a rotationally symmetrical corrugated divider arranged over the entire circumference. The partial mass flow 2 flowing out of the manifold 20 eccentrically is broken down along the entire orbit by a fixed fan collar of the corrugated divider into successive individual samples 5 of the same size.

The horizontally consecutive compartments of the corrugated divider are arranged in such a way that all individual samples which are dropped onto an inwardly inclined long fan base 44 are returned to the main stream and all individual samples which fall on an outwardly inclined short fan base 45 as a divided analysis sample stream 3 subtracted from. In this way, every second individual sample 5 arrives at the analysis sample stream 3. The fixed division ratio of 1: 2 thus achieved is insensitive to mass flow fluctuations from the removal opening 10, since integration over the entire cross-section immediately compensates for sectoral overloads and underloads. For this reason, it is not necessary in this arrangement to operate the removal opening 10 at a different angular speed than the downstream distributor pipe 20 for the transfer to the sample divider. The design solution and the drive in the sampler are correspondingly simpler. Deflection cone 17, mouth funnel 18 with outlet opening 19 and distributor pipe 20 are connected to form a structural unit which is driven by the motor 14 via a gear 15 'at a constant angular velocity w. The drive via the motor 14 alternatively takes place from below, where. it is arranged protected together with the gear 15 'under a rotating conical hood 46. The driven elements 17, 18, 20, 22, 23, 25, 26 and 46 are rotatably mounted centrally on the bearing block 29.

All individual samples 5, which are drawn off over the short compartment bases 45, fall out of the housing 34 of the sample divider into a flanged collecting container 47 and hit the inclined safety sieve 38 on the side opposite the sample dispensing tubes 39 and a spray-grain outlet shaft 48. To avoid short-circuit currents the partial streams of the individual samples from the opposite half-space are returned via a deflection chute 49 to the center of the collecting container 47 and are also directed there to the safety sieve 38. This ensures that a sufficiently long sieve section can be effective for all partial mass flows before the oversize or sprayed grain that has been separated off is drawn off through the spraying grain outlet shaft 48 and the sieve passage for further use via the sample delivery tube 39 as the analysis sample stream 3. With an additional connecting element 74, the oversize can be returned directly to the main product stream via a return shaft 75 or removed from the process with a switch 76 via an outlet nozzle 77 for control purposes.

Another embodiment of the security screening located outside of the sampler and divider housing 16, 60 is shown in FIG. 6. In the case of changing spray grain proportions, it can happen that the arrangement of the safety screen 38 shown in FIG. 5 does not sufficiently remove contaminants or particles outside the measuring range. The cascade connection of the simple classifying elements 99 shown in FIG. 6 permits flexible adaptation, both to changing quantities and to different separation limits. Each element consists of two half-shells. An upper half-shell 86 has an inlet connection 88 at its upper end, which is flanged directly to the outlet connection 39 of the sample divider 60 in the top classifying element 99 in the side view in FIG. 6.

The analytical sample stream 3 thus taken over from the sample divider, which e.g. still contains spray particles 7 falls through the inlet connection 88 directly onto the safety sieve 38. This sieve is clamped between two half-shells 86 and 87 and is dimensioned such that the spray particles are retained as coarse material by the sieve, while the analyzable sample stream 3 passes through as fine material. The coarse material runs off via the safety sieve 38 and reaches the coarse material outlet connection 90 of a lower half-shell 87 in the lower part of a classifying element 99. The safety sieve 38 itself is shorter than the classifying element 99 and is so long that a fine material located further up Outlet port 89 of the lower half-shell 87 is completely covered and short-circuit currents are just avoided. The length and steepness of the classification elements are determined on the one hand by the permissible length of stay, which should be as short as possible, and on the other hand by the required selectivity. It is easy to adapt to this and to changing process conditions with classifying elements 99 designed in this way, in that classifying elements 99 of identical construction are now connected to the outlet connections 89 and 90 of the first lower half-shell 87. This leads to a re-screening of the fine as well as the coarse material of the first stage. Depending on the task, this sieve or a correspondingly adjusted sieve mesh size can be used in these downstream stages. In Fig. 6, the respective fine material of the downstream classification elements for the total fine material F or the analysis sample stream 3 without spray grain and the respective coarse material for the total coarse material G or for the amount of the spray grain parts are combined by means of suitable Y-pipe pieces.

In addition to the circuit variant shown and described, any other combinations of structurally identical classification elements 99 are conceivable. A very clear elimination of the spray grain would be achievable, for example, with a multiple series connection of classifying elements at the lower coarse material outlet, while the fine material could be composed of the respective passages at the upper fine material outlets without further reclassification. Conversely, a finely divided fine material could be produced in a targeted manner.

Another circuit variant could be set up with the aim of performing multiple classification. For this purpose, the mesh sizes of the safety sieve 38 would have to be graded accordingly in the case of the successive classification elements.

The mesh sizes behind the fine material outlets would have to become increasingly smaller and the mesh sizes behind the coarse material outlets correspondingly larger. A multiple classification behind the sampling would, for example, be used for gravimetric analysis of the course of a particle size distribution outside the measuring range of a downstream sample analyzer.

Variants for the simultaneous production of sharp classification cuts and for multiple classification can also be combined in series and in parallel.

To support screening, e.g. a double-acting vibration drive 51 installed between the classifying elements.

Partial section A-D in FIG. 6 shows the assignment of the sieve cascade to the representations in FIGS. 2, 3 and 4.

7 shows the top view A = D and a modified longitudinal section K-K of FIG. 5 in partial sections.

In the lower left quadrant in the AB sector, the top view of FIGS. 2 and 4 is repeated for orientation. The two overhead quadrants CD show the fan collar of the corrugated divider with the short fan bases 45 and the long fan bases 44, via which the individual samples 5 are returned to the main product stream 1.

• M _A/ M_H = (α/360°) • (1/2^k) = α/(360°• 2^k),

wobei über die Variation von k (nur ganzzahlig) alle Quoten möglich sind. Die Anordnung ist aber nicht verwendbar, wenn eine Anpassung an - schwankende oder geänderte Hauptmassenströme im Prozeßbetrieb erforderlich ist.The individual samples 5 fall down from the short compartment floors 45 through the crossed-out opening trapezoids in the direction of gravity. Section KK also shows the variant with which the sample division ratio can be adjusted. The first division stage consisting of elements 34, 44 and 45 is followed by a second, structurally identical corrugated divider arrangement. A homogenous transverse distribution over the cross section is brought about by a permeable intermediate floor 50. To be on the safe side, the units of the corrugated dividers are rotated by half a compartment width. This series connection can be repeated k times and thus set a sample division ratio of 1: 2k. The required analysis sample stream 3 is adjusted in this combination by the number of stages k and the extraction angle a accordingly:

• M _A / M _H = (α / 360 °) • (1/2 ^k ) = α / (360 ° • 2 ^k ),

where all odds are possible by varying k (only whole numbers). However, the arrangement cannot be used if an adaptation to fluctuating or changed main mass flows is required in process mode.

In the quadrant EH of the top view AD, the arrangement of the spray grain outlet shaft 48 and the sample delivery tube 39 is shown.

Claims (26)

1.Procedure for sampling from streams of dispersed products from transport lines or at product transfer points and sample splitting onto an analytical sample stream suitable for a subsequent sample analysis, in which a partial sample is taken from a main product stream and an analytical sample stream and a residual partial stream is obtained from this partial sample, from which the the first can be fed to a sample analysis and the second is returned to the main product stream or discarded,
characterized in that sampling and sample division are carried out continuously in-line immediately in succession, and with the sampling a representative partial sample stream of up to 1/100 of the main product stream is generated and with the subsequent sample division a representative division of this partial stream by up to three powers of ten to produce a Analysis sample stream is carried out, for which purpose the individual sample streams generated during sample division are individually or randomly combined in such a way that the subsequent sample analysis can be carried out directly on-line without any noticeable time-delaying intermediate storage. 2. The method according to claim 1,
characterized,
that in production processes with changing product main streams M _H, a first adaptation to the changing product main stream M _H takes place at the point of sampling and the sample division is carried out so proportionally to the first adaptation as a second adjustment and / or that the analysis sample stream M is proportional to Product main flow MH takes place. 3. The method according to claim 1 or 2,
characterized,
that when the main product flow is free of means of transport, sampling and sample division take place in succession in the direction of gravity in a rotationally symmetrical vertical transport line (chutes) at a product transfer point. 4. The method according to claim 1 or 2,
characterized,
that from a rotationally symmetrical transport line, the sampling of dispersed products carried in a fluid carrier stream takes place by suctioning off a representative fluid partial stream through a rotating removal opening and is adjusted in proportion to the isokinetic conditions at the point of sampling or readjusted on-line. 5.Device for sampling from streams of dispersed products from transport lines or at product transfer points and sample division into an analysis sample stream suitable for a subsequent sample analysis with a sampler for sampling from a rotationally symmetrical product main stream transport line for obtaining a partial sample and a sample divider downstream of it for obtaining an analysis sample stream from the Partial sample that can be fed directly to an analysis device, in particular for carrying out a method according to one of claims 1 to 4,
characterized,
that a pro in the product stream transportation line User (9) for obtaining a partial flow (2) of up to 1: 100 of the main product stream (1) from the main product stream (1) with a removal head (12) which can be driven in rotation, is provided at the entrance to a removal line (30), the removal opening ( 10) designed as at least one circular sector with an opening angle (a) and which can be rotated with the sector tip about the central axis of the main product flow transport line,
that the sampling line (30) opens directly into a sample divider (60) for dividing the partial stream (2) into an analysis sample stream (3) and a residual partial stream (4) and
that the sample divider (60) divides the partial stream (2) up to 1: 1000 into the analysis sample stream (3). 6. The device according to claim 5,
characterized, .
that the sample divider (60) has a dividing funnel (35) narrowing in the flow direction with at least one, in particular circular sector-shaped part opening (36) with the passage opening angle (β), to which the partial flow (2) can be applied off-center, rotating about its axis, and on the central outlet opening (35 ') is followed by a return pipe (37) for discharging the residual partial stream (4) and the partial opening (36) is followed by a sample delivery tube (39) for the analysis sample stream (3). 7. The device according to claim 6,
characterized,
that the partial opening (36) is followed by a safety sieve (38) for the retention of spray or oversize or non-analyzable coarse grain, which leads this grain in particular into the return pipe (37). 8.Device according to claim 5,
characterized,
that a deflection cone (59) is provided in the center of rotation of the sector-shaped removal opening (10), the base of which is so large that the smallest removal opening located close to the pivot point is considerably larger than the coarsest particles in the main product stream (1). 9.Device according to claim 5,
characterized,

that an intermediate sieve (61) is provided in front of the removal opening (10) in order to equalize the incoming main product stream (1). 10. The device according to one of claims 5 to 9,
characterized,
that the removal opening angle (a) of the removal opening (10) of the removal head (12) and / or the passage opening angle (β) of the dividing funnel (35) can be changed (by means of funnel segment (43) of the part opening (36)). 11. The device according to one of claims 5 to 10,
characterized,
that the removal head (12) of the sampler (9) can be driven with a different rotational speed than the sample divider rotor of the sample divider (60). 12. The device according to claim 11,
characterized,
that the rotary drive (14) of the sampling head (12) of the sampler (9) is designed to be variable in speed. 13. Device according to one of claims 11 or 12,
characterized,
that a distributor pipe (20) downstream of the sampler (9) and feeding the sample divider (60) can be driven in rotation at a variable speed. 14. The device according to one of claims 10 to 12,
characterized,
that the sample divider passage opening angle (.beta.) on a ring sector can be changed between 0 ° and 90 °, at most 180 °, by adjusting a funnel segment (43) arranged above or below the part opening (36) to partially or completely cover the part opening (36) is. 15. The apparatus according to claim 5,
characterized,
that the sample divider (60) has a divider funnel (35) with up to 32 hinged chutes (41) arranged on a circular arc in an angular range of up to 90 °, at most 180 °, which are opened or closed individually or in groups to adjust the opening angle can. 16. The apparatus according to claim 5 or 11, characterized in
that the sample divider (60) is designed as an isokinetic suction sample divider and to set a passage opening angle (β) in its rotationally drivable cylindrical head piece (31) and in its downstream elongated cylindrical stator (32) stationary sector-shaped guide channels (33) are formed and partial flows behind the stator (32) can be combined individually or in groups in a downstream concentrator (71). 17. The apparatus of claim 10,
characterized,
that the sampling head (12) of the sampler (9) can be exchanged for an identical sampling head with a different sampling opening (10). 18. Device according to one of claims 5 to 17,
characterized,
that the removal head (12) symmetrically or asymmetrically arranged sector-shaped Ent has receiving openings with the same or different removal opening angles (a _" a _z ). 19. The apparatus of claim 5,
characterized,
that the sample divider (60) from k series-connected corrugated dividers, each with a passage opening angle (ß) of. Is formed 180 °, which cause the division of the partial flow MA (2) in relation to the main flow M _H (1) corresponding to M _A / M _H = (α / 360 °) • (1/2 ^k ). 20. Device according to one of claims 5 to 19,
characterized,
that the sample divider (60) has an inclined safety sieve (38) in front of its sample delivery tube (39) for separating disruptive or non-analyzable coarse particles from the analysis sample stream (3). 21.Device according to claim 20,
characterized,
that a sequence of tubular classifying elements (99) each consisting of two half-shells (86, 87) with built-in sieve (38) is provided for safety screening. 22.The device according to claim 21,
characterized,
that the upper half-shell (86) has a feed pipe (88) at the upper end. 23.The device according to claim 21,
characterized,
that the lower half-shell (87) has two outlet connections (89, 90) at the lower end, of which the outlet connection (89) for the fine material discharge sits above the outlet connection (90) for the coarse material discharge. 24.Device according to claim 21 and 22, characterized in
that the sieve (38) between the half-shells (86, 87) is just long enough to cover the outlet connection (89) located in the lower half-shell (87) for the fine material discharge. 25. The device according to claim 20,
characterized,
that the safety sieve (38) interacts at least one deflection chute (49) for the sample streams (5) in such a way that they all find a sufficiently long sieving section for safe separation. 26. Device according to one of claims 5 to 11,
characterized,
that samplers (9) and / or sample dividers (60) can be set in vibration behind chutes or pipes to support particle movement on wall and sieve surfaces by means of a vibrator (51).

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